CN114060255B - A magnetorheological fluid micropump driven by a gradient magnetic field - Google Patents

Abstract

The present invention proposes a magneto-rheological fluid micropump driven by a gradient magnetic field. The micropump includes an electromagnet and an elastic pump cavity; an inlet valve is provided at the input port of the pump cavity to prevent liquid from flowing out of the pump cavity. The output port is provided with an outlet valve to prevent the inflow of liquid in the pump chamber; the elastic pump chamber is provided with an elastic magnetorheological fluid container; when the excitation coil of the electromagnet is energized, the magnetorheological fluid in the magnetorheological fluid container Under the action of the magnetic field, it flows and drives the deformation or displacement of the magnetorheological fluid container, drives the deformation of the pump cavity and squeezes the liquid in the pump cavity to be output from the output port; when the excitation coil is powered off, the magnetorheological fluid container and the pump cavity are under elastic force Reset under the action to form a negative pressure in the pump chamber and suck the external liquid into the pump chamber through the input port; the invention has simple structure, small volume and fast response speed, and will not cause secondary pollution and damage to the pumped liquid, and can be applied to Delivery of high-quality liquids such as biological medicines and chemical reagents, and as a power source for micro-mechanical systems.

Description

A magnetorheological fluid micropump driven by a gradient magnetic field

technical field

The invention relates to the technical field of liquid pumps, in particular to a magnetorheological fluid micropump driven by a gradient magnetic field.

Background technique

Hydraulic pumps play a very important role in industrial production and are the most important mechanical components in many hydraulically driven equipment such as construction machinery and pipeline transportation equipment. Existing traditional hydraulic pumps mainly include gear pumps, plunger pumps, vane pumps, diaphragm pumps and peristaltic pumps, all of which are driven by motors or engines. The existing hydraulic pumps mainly have the following problems:

1. The mechanical moving parts of the gear pump, vane pump and plunger pump will directly contact the pumped fluid itself during the working process, so it will pollute the fluid, and the noise is loud during operation, and the mechanical parts are seriously worn;

2. Diaphragm pumps and peristaltic pumps have less damage and pollution to the pumped liquid, but because they also use motors as the mechanical power source, the structure is complex and the volume cannot be greatly reduced, which limits their application range;

3. The tubular peristaltic pump made of magnetorheological elastomer has a small effective pump cavity volume, and it takes a long time for the elastomer tube to return to its original shape after deformation, resulting in the inability to increase the frequency of compressing the pump cavity and affecting the output flow.

As a smart material, magnetorheological fluid (MRF) is made by mixing micron-scale or nano-scale magnetic particles, non-magnetic carrier fluids such as kerosene or silicone oil, and some modifying additives. Under the action of an external magnetic field, it can change from a fluid state to a semi-solid state with a response speed of milliseconds. Magnetorheological fluids have also attracted widespread attention due to this unique rheological property. In recent years, devices using magnetorheological effects such as magnetorheological dampers, brakes, shock absorbers, polishing devices, etc. have been continuously researched, and they have good applications in vehicle engineering, civil engineering, aerospace, medicine and other fields prospect.

It is unprecedented to use magnetorheological fluid as a driving component in a pump, but at the same time it is an application direction with considerable development potential. Under the action of the gradient magnetic field, the magnetorheological fluid will be subjected to a pulling force along the maximum direction of the magnetic field gradient, and the pulling force will increase with the increase of the magnetic field gradient. Therefore, the magnetic field can be used as a power source, the magnetorheological fluid can be used as a driving part, and a magnetorheological fluid pump can be made with a certain elastic structure. The magneto-rheological fluid pump will have the advantages of simple structure, flexible driving, and high reliability.

Contents of the invention

The invention proposes a magnetorheological fluid micropump driven by a gradient magnetic field, which has a simple structure, small volume, and fast response speed, and will not cause secondary pollution and damage to the pumped liquid, and can be applied to biological medicines, chemical reagents, etc. Delivery of high-quality liquids and as a power source for micro-mechanical systems.

The present invention adopts the following technical solutions.

A magneto-rheological fluid micropump driven by a gradient magnetic field, the micropump includes an electromagnet (7) and an elastic pump chamber; the inlet of the pump chamber is provided with an inlet valve ( 5), the output port is provided with an outlet valve (2) to prevent the inflow of liquid in the pump chamber; the elastic pump chamber is provided with an elastic magneto-rheological fluid container (1); when the excitation coil (3) of the electromagnet is energized , the magnetorheological fluid in the magnetorheological fluid container flows under the action of the magnetic field and drives the deformation or displacement of the magnetorheological fluid container, drives the deformation of the pump chamber and squeezes the liquid in the pump chamber to be output from the output port; when the excitation coil is powered off At this time, the magnetorheological fluid container and the pump chamber are reset under the action of elastic force, so that negative pressure is formed in the pump chamber and the external liquid is sucked into the pump chamber through the input port.

The pump body (4) of the micro-pump is made of elastic material; the magnetorheological fluid container is integrally formed with the pump body, which is the magnetorheological fluid cavity in the middle of the upper part of the pump body; the pump cavity of the pump body passes through the input port It communicates with the input pipeline; the magnetorheological fluid container is located on the upper part of the pump chamber; the electromagnet is arranged below the pump chamber.

When the excitation coil of the electromagnet is powered off and the reset of the magneto-rheological fluid container is completed, the inlet valve and the outlet valve remain in a normally closed state, and the magneto-rheological fluid chamber is in the shape of an ellipsoid, with the larger bottom surface facing the electromagnet; When the iron excitation coil is energized, the ellipsoidal magnetorheological liquid mass in the magnetorheological fluid chamber is affected by the magnetic force of the electromagnet, and the middle part is sunken and the top of the pump chamber is sunken, the inlet valve is closed, and the outlet valve is opened. The liquid is extruded from the output port.

The lumen at the junction of the input pipeline and the input port of the pump chamber is an ellipsoidal cavity (6).

The volume and radius of the ellipsoidal magnetorheological fluid mass are larger than the volume and radius of the ellipsoidal cavity of the input pipeline.

The electromagnet is arranged under the pump body, or is close to the bottom surface of the pump body, and its magnetic attraction direction is towards the magnetorheological fluid mass in the magnetorheological fluid cavity; when the magnetorheological fluid micropump is working, the electromagnet The excitation coil is fed with pulse current to periodically generate a gradient magnetic field in the pump body, so as to periodically pull the magnetorheological fluid group in the magnetorheological fluid chamber toward the direction of the electromagnet.

The inlet valve and outlet valve are conical.

The working process of the magnetorheological fluid micropump includes the following steps;

Step S1, there is no current in the excitation coil (3), the pump body (4) is in a naturally relaxed state, the inlet valve (5) and the outlet valve (2) are in a tightly closed state, the input pipeline (61), the output pipeline (62), The pump chambers (63) are not connected to each other;

Step S2, pass the excitation current into the excitation coil (3), the electromagnet will generate a gradient magnetic field B in the pump body (4) and pull the magnetorheological fluid mass towards the iron core (72) of the electromagnet at the speed v At the same time, the pump body (4) is elastically deformed; the magnetorheological fluid mass (1) squeezes the liquid in the pump cavity when it is close to the iron core, and the outlet valve (2) is under the action of hydraulic pressure Open and the inlet valve (5) remains closed, and the liquid is exported from the outlet pipe (62) to the pump body;

Step S3, the excitation current is continuously fed into the excitation coil (3), the pump body (4) remains deformed, the outlet valve (2) is closed, the inlet valve (5) is kept tightly closed, the input pipeline (61), the output pipeline ( 62), the pump chambers (63) are not connected to each other;

Step S4, turn off the current in the excitation coil (3), and the magnetorheological liquid mass (1) is pulled back to the initial position under the action of the elastic force of the pump body (4), at this time, the pump cavity (63) generates a negative pressure, prompting the inlet valve (5) to open and the outlet valve (2) to remain closed, the pumped liquid flows from the inlet valve (5) through the inlet pipe (61) and fills the entire pump cavity (63);

When the magnetorheological fluid micropump is working, a pulse current is passed into the excitation coil, and the above four steps can be repeated to continuously transport the fluid.

The pump body is made of silicone material.

The electromagnet includes an iron core, an excitation coil and an outer ring magnetic conduction structure. The iron core is arranged inside the excitation coil, and an outer ring magnetic conduction structure is also provided outside the excitation coil. The ring structure of the rheological liquid mass, when the electromagnet excitation coil is energized, the magnetic force of the outer ring magnetic structure attracts the edge of the magnetorheological liquid mass to prevent the edge of the magnetorheological liquid mass from sinking excessively.

The invention has the advantages of simple structure, small volume, fast response speed, no secondary pollution and damage to the pumped liquid, and can be applied to the delivery of high-quality liquids such as biological medicines and chemical reagents and as the power source of micro-mechanical systems.

Description of drawings

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

Accompanying drawing 1 is the schematic sectional view of the present invention;

Accompanying drawing 2 is the schematic diagram of working steps of micropump of the present invention;

In the figure: 1- magnetorheological fluid container; 2- outlet valve; 3- excitation coil; 4- pump body; 5- inlet valve; 6- ellipsoid cavity; 7- electromagnet;

61-input pipeline; 62-output pipeline; 63-pump cavity; 71-outer ring magnetic structure; 72-iron core.

Detailed ways

As shown in the figure, a magneto-rheological fluid micropump driven by a gradient magnetic field, the micropump includes an electromagnet 7 and an elastic pump chamber; The inlet valve 5 is provided with an outlet valve 2 at the output port to prevent the inflow of liquid in the pump chamber; the elastic pump chamber is provided with an elastic magnetorheological fluid container 1; when the excitation coil 3 of the electromagnet is energized, the magnetorheological fluid The magnetorheological fluid in the container flows under the action of the magnetic field and drives the deformation or displacement of the magnetorheological fluid container, which drives the deformation of the pump cavity and squeezes the liquid in the pump cavity to be output from the output port; when the excitation coil is powered off, the magnetorheological fluid The liquid container and the pump chamber are reset under the action of elastic force, so that negative pressure is formed in the pump chamber and the external liquid is sucked into the pump chamber through the input port.

The pump body 4 of the micro pump is made of elastic material; the magnetorheological fluid container and the pump body are integrally formed, which is the magnetorheological fluid cavity in the middle of the upper part of the pump body; the pump cavity of the pump body is connected to the input port through the input port. The pipelines are connected; the magnetorheological fluid container is located on the upper part of the pump chamber; the electromagnet is arranged below the pump chamber.

When the excitation coil of the electromagnet is powered off and the reset of the magneto-rheological fluid container is completed, the inlet valve and the outlet valve remain in a normally closed state, and the magneto-rheological fluid chamber is in the shape of an ellipsoid, with the larger bottom surface facing the electromagnet; When the iron excitation coil is energized, the ellipsoidal magnetorheological liquid mass in the magnetorheological fluid chamber is affected by the magnetic force of the electromagnet, and the middle part is sunken and the top of the pump chamber is sunken, the inlet valve is closed, and the outlet valve is opened. The liquid is extruded from the output port.

The lumen at the junction of the input pipeline and the inlet of the pump cavity is an ellipsoid cavity 6 .

The volume and radius of the ellipsoidal magnetorheological fluid mass are larger than the volume and radius of the ellipsoidal cavity of the input pipeline.

The electromagnet is arranged under the pump body, or is close to the bottom surface of the pump body, and its magnetic attraction direction is towards the magnetorheological fluid mass in the magnetorheological fluid cavity; when the magnetorheological fluid micropump is working, the electromagnet The excitation coil is fed with pulse current to periodically generate a gradient magnetic field in the pump body, so as to periodically pull the magnetorheological fluid group in the magnetorheological fluid chamber toward the direction of the electromagnet.

The inlet valve and outlet valve are conical.

The working process of the magnetorheological fluid micropump includes the following steps;

Step S1, there is no current in the excitation coil 3, the pump body 4 is in a naturally relaxed state, the inlet valve 5 and the outlet valve 2 are in a tightly closed state, and the input pipe 61, the output pipe 62, and the pump chamber 63 are not connected to each other;

Step S2, pass the excitation current into the excitation coil 3, the electromagnet will generate a gradient magnetic field B in the pump body 4 and pull the magnetorheological liquid mass to approach the iron core 72 of the electromagnet at the speed v, and at the same time cause the pump body 4 Elastic deformation occurs; the magnetorheological liquid mass 1 squeezes the liquid in the pump cavity when it is close to the iron core. At this time, the outlet valve 2 is opened under the action of hydraulic pressure and the inlet valve 5 is kept closed. The liquid flows from The output pipeline 62 leads out of the pump body;

Step S3, the excitation current is continuously fed into the excitation coil 3, the pump body 4 remains deformed, the outlet valve 2 is closed, the inlet valve 5 is kept tightly closed, and the input pipe 61, the output pipe 62, and the pump chamber 63 are not connected to each other;

Step S4, turn off the current in the excitation coil 3, and the magnetorheological fluid mass 1 is pulled back to the initial position under the action of the elastic force of the pump body 4. At this time, the pump cavity 63 generates a negative pressure, which prompts the inlet valve 5 to open and The outlet valve 2 remains closed, and the pumped liquid flows in from the inlet valve 5 through the input pipe 61 and fills the entire pump chamber 63;

When the magnetorheological fluid micropump is working, a pulse current is passed into the excitation coil, and the above four steps can be repeated to continuously transport the fluid.

The pump body is made of silicone material.

The electromagnet includes an iron core, an excitation coil and an outer ring magnetic conduction structure, the iron core is arranged on the inside of the excitation coil, and an outer ring magnetic conduction structure 71 is also provided outside the excitation coil, and the outer ring magnetic conduction structure forms a top-view area larger than The ring structure of the magnetorheological fluid mass, when the electromagnet excitation coil is energized, the magnetic force of the outer ring magnetic structure attracts the edge of the magnetorheological fluid mass to prevent the edge of the magnetorheological fluid mass from sinking excessively.

In this example, the magnetorheological fluid is made by mixing micron-scale or nano-scale magnetic particles, non-magnetic carrier fluids such as kerosene or silicone oil, and some modifying additives. Under the action of the external gradient magnetic field, each magnetically permeable particle in the magnetorheological fluid will receive an attractive force along the direction of the maximum magnetic field gradient, and the whole magnetorheological fluid is pulled to the position with the highest magnetic flux density from a macroscopic perspective. .

The electromagnet in this example can generate a gradient magnetic field in the pump body, so as to pull the ellipsoidal magnetorheological fluid mass to the electromagnet, and squeeze the pipeline cavity, and then pass through the valve structure with one-way opening and closing Pump the liquid out of the cavity.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (4)

1. A magneto-rheological fluid micropump driven by a gradient magnetic field, characterized in that: the micropump includes an electromagnet (7) and an elastic pump chamber (63); the input port of the pump chamber is provided with an anti-pump The inlet valve (5) through which the liquid in the chamber flows out, and the outlet valve (2) which prevents the liquid in the pump chamber from flowing in is provided at the output port; the pump chamber is provided with an elastic magneto-rheological fluid container (1); when the electromagnet When the excitation coil (3) is energized, the magnetorheological fluid in the magnetorheological fluid container flows under the action of the magnetic field and drives the deformation or displacement of the magnetorheological fluid container, which drives the deformation of the pump cavity and squeezes the liquid in the pump cavity from the output port. Output; when the excitation coil is powered off, the magneto-rheological fluid container and the pump chamber are reset under the action of elastic force, so that negative pressure is formed in the pump chamber and the external liquid is sucked into the pump chamber through the input port; The pump body (4) of the micropump is made of elastic material; the magnetorheological fluid container and the pump body are integrally formed, which is the magnetorheological fluid cavity in the middle of the upper part of the pump body; the pump cavity of the pump body is connected to the pump body through the input port. The input pipelines are connected; the magnetorheological fluid container is located on the upper part of the pump chamber; the electromagnet is arranged below the pump chamber; When the excitation coil of the electromagnet is powered off and the reset of the magneto-rheological fluid container is completed, the inlet valve and outlet valve remain in a normally closed state, and the magneto-rheological fluid cavity is ellipsoidal; when the excitation coil of the electromagnet is energized, the magneto-rheological fluid The ellipsoidal magnetorheological liquid group in the liquid chamber is affected by the magnetic force of the electromagnet, and the middle part is concave and the top of the pump chamber is concave, the inlet valve is closed, the outlet valve is opened, and the liquid in the pump chamber is squeezed out from the output port; The electromagnet is arranged under the pump body, and its magnetic attraction direction faces the magnetorheological fluid mass in the magnetorheological fluid cavity; A gradient magnetic field is periodically generated in the pump body to periodically pull the magnetorheological liquid mass in the magnetorheological fluid chamber toward the direction of the electromagnet; The electromagnet includes an iron core, an excitation coil and an outer ring magnetic conduction structure. The iron core is arranged inside the excitation coil, and an outer ring magnetic conduction structure is also provided outside the excitation coil. The ring structure of the rheological liquid mass, when the electromagnet excitation coil is energized, the magnetic force of the outer ring magnetic structure attracts the edge of the magnetorheological liquid mass to prevent the edge of the magnetorheological liquid mass from sinking excessively; When the magnetorheological fluid mass in the magnetorheological fluid cavity is pulled toward the direction of the electromagnet, the middle part of the magnetorheological fluid mass is concave and the edge is lifted. 2 . The magneto-rheological fluid micropump driven by a gradient magnetic field according to claim 1 , wherein the inlet valve and the outlet valve are conical. 3. The magnetorheological fluid micropump driven by a gradient magnetic field according to claim 1, wherein the working process of the magnetorheological fluid micropump comprises the following steps; Step S1, there is no current in the excitation coil (3), the pump body (4) is in a naturally relaxed state, the inlet valve (5) and the outlet valve (2) are in a tightly closed state, the input pipeline (61), the output pipeline (62), The pump chambers (63) are not connected to each other; Step S2, pass the excitation current into the excitation coil (3), the electromagnet will generate a gradient magnetic field B in the pump body (4) and pull the magnetorheological fluid mass towards the iron core (72) of the electromagnet at the speed v At the same time, the pump body (4) is elastically deformed; the magnetorheological fluid mass squeezes the liquid in the pump chamber when it approaches the iron core, and the outlet valve (2) opens under the hydraulic pressure and the inlet valve The valve (5) is kept closed, and the liquid is exported from the output pipe (62) to the pump body; Step S3, the excitation current is continuously fed into the excitation coil (3), the pump body (4) remains deformed, the outlet valve (2) is closed, the inlet valve (5) is kept tightly closed, the input pipeline (61), the output pipeline ( 62), the pump chambers (63) are not connected to each other; Step S4, turn off the current in the excitation coil (3), and the magnetorheological liquid mass is pulled back to the initial position under the action of the elastic force of the pump body (4). The inlet valve (5) is opened while the outlet valve (2) is kept closed, and the pumped liquid flows from the inlet valve (5) through the inlet pipe (61) and fills the entire pump cavity (63); When the magnetorheological fluid micropump is working, a pulse current is passed into the excitation coil, and the above four steps can be repeated to continuously transport the fluid. 4 . The magnetorheological fluid micropump driven by a gradient magnetic field according to claim 1 , wherein the pump body is made of silica gel. 5 .

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